Relocating the AKI USB keyboard mod PCB - improvised solution in an 800XL

[Beeblebrox]

Basically with my latest aquisition, yet another 800XL, I have a Simple Stereo Mod board already in place and recently an AKI USB keyboard mod board. Happily installed the latter the other day by piggy backing the AKI USB mod pcb on top of the simple stereo board, (plugged into the lower Pokey socket), and eveything worked:

         

 

(Incidentally I'd made up a cable from a cheap header to USB port (shielded) cable I picked up and modded to hook up the 4 x function keys and all has been working fine, with the 800XL's casing open. (I've left open as been installing other mods including UAV r.D and generally tinkering)).

 

Over the weekend I then went to pop the top casing/keyboard back on and realised the sum total stack height of these 2 x mods and 2nd Pokey chip meant the casing wasn't gonna fit, with around 1cm of height I'd needed to lose:

 

 

The 800XL board is manufactured in Hong Kong as a such all socketed. On top of this height wise it didn't help that the simpe stereo and AKI boards obviously also have sockets adding to the height even before you plug in the 2nd Pokey.

 

I mulled over a few solutions:

 

Option 1) I could remove the 800XL Pokey socket from the mainboard and also the sockets from the AKI and simple stereo pcb and solder the chips directly to each but that would have been a major pain. It could have damaged anything at any stage during the desoldering/soldering process, and besides the height reduction might still not have been enough. Plus if I ever needed to replace or remove anything down the line it would have made it so much harder.

 

Option 2) I find a way to relocate the AKI USB pcb using some kind of 40pin adapters and cabing/wiring.

 

I started looking down the 2nd option and whilst I did find the following 40pin solderless DIP adapters, which I could have hooked up either end of some cabling, it still would have presented issues:

 

 

The height issue of the adapters either end would likely still be a problem and restrict where I would place this elsewhere. (There are lots of mods already crammed into this particular 800XL's casing). Besides, try as I might I couldn't source these adapters in the UK, only in the US.

 

In the end I came up with my own solution using parts I had to hand which - whilst grated are not particularly pretty - works.

 

Using my last precision 40pin socket, some spare IDE ribbon cabling, and a lot of patience, I made my own adapter:

 

   

 

80 x solder points later, it plugs into the lower Pokey socket of the Simple stero pcb, and the other end with the AKI usb pcb and mounted 2nd Pokey chip tucks into the top right of the 800XL, between the U1MB pcb, near the SIO and 2nd joystick port:

 

 

I triple checked my solder work for shorts and made sure all was secure/didn't shift. I also made sure I shielded any solder points and components from shorting on the 800XL's pcb, the AKI pcb, and my cable adapter's solder points and components. My existing cabling for the AKI board for the Usb port and function keys still fitted thankfully.

 

Case fitted perfectly first time, and everything works with a wireless keyboard, stereo output, etc:

 

 

 

 

All in, because of having to modify, separate, strip and tin the IDE ribbon cabling and solder 80 x points, it was around 2-3 hrs work. 

 

Soldering the wires into the 40pin socket was the biggest pain as you are dealing with a few mm of wiring inserted into very tiny holes spaced mm's apart. Try as I might I couldn't avoid melting the socket's plastic a little each time.

 

I have no doubt there are better and neater ways to resolve this but with the parts I had to hand and despite this looking a little messy it's secure and ultimately does the trick.
 

Edited August 10, 2021 by Beeblebrox
adding more info

[+mytek]

Maybe you should have considered this all-in-one solution.

 

Info Link

Buy Link

 

EDIT: but I now see that you got a USB keyboard interface, which allowed for a wireless keyboard.

 

[Beeblebrox]

6 hours ago, mytek said:

Maybe you should have considered this all-in-one solution.

 

Info Link

Buy Link

 

EDIT: but I now see that you got a USB keyboard interface, which allowed for a wireless keyboard.

 

@mytekThanks for the link. Looks a great solution. However yes I required a USB keyboard connection.

Basically I bought the 800XL pre installed with the simple stereo mod/switch/audio jacks.

I've got the same AKI usb mod in another A8 which works well.

Besides that the AKI mod is available in the UK at a pretty affordable price including free p&p.

 

My rather crude relocation mod adapter was just something I knocked up on the spot after realising the case wouldn't close. 

Edited August 11, 2021 by Beeblebrox
Typos

[hueyjones70]

Does the external keyboard disable the stock keyboard?

[Beeblebrox]

8 hours ago, hueyjones70 said:

Does the external keyboard disable the stock keyboard?

@hueyjones70  Not at all - both work happily alongside each other.